Adjustable crank-hanger.



I G. L. JENNBSS. ADJUSTABLE CRANK HANGER. APPLICATION FILED JAN. 25, 1910.

Patented Mar.21, 1911.

CHARLES L. JENNESS,

0F CHICAGO, ILLINOIS.

ADJUSTABLE CRANK-HANGER.

Application filed January 25, 1910.

To all whom it may concern:

Be it known that I, CHARLES L. Jnnivnss, a citizen of the United States, residing at Chicago, in the county of Cook and State of lllinois, have invented certain new and useful lmprovements in Adjustable Crank- Hangers, of which the following is a speciiication.

This invention is designed more particularly for use in bicycle repairing, although it is not the intention to limit the invention strictly to this iield.

In the construction of bicycles it frequently happens that the different makers employ crank hanger brackets of different widths, which serves to vary the distance between the crank arms, with resulting differences in the lengths of crank shafts employed. ln repairing bicycles having crank shafts of different lengths, difficulty and delay are often experienced by reason of the fact that the repair man is unable to furnish a shaft of the proper length to fit the hanger bracket of the bicycle undergoing repairs, and this frequently necessitates the procuring of new parts from the original maker, which is usually inconvenient, and sometimes impossible.

The object of the present invention is to obviate the difficulties above mentioned by providing a crank shaft of a maximum length, which can be cut down to suit particular requirements, and the invention more particularly relates to the means for fastening the crank arms to a shaft of this character at the proper points to accommodate the width of the hanger bracket. p

Further objects will appear from a detailed description of the invention, which consists in the features of construction and combination of parts hereinafter described and claimed.

In the drawings, Figure l is a view partly in section, showing the end of the crank shaft with the associated parts; Fig. l, a longitudinal sectional detail of the wedge cotter pin which cooperates with the shaft; Fig. 2, a side elevation of the sprocket wheel and cra-nk arm, showing the end of the shaft and the Cotter pin driven to place; and Fig. 3, a perspective detail, partly in section and enlarged, showing the method of driving the cotter in.

lt will be understood that the parts particularly relating to the present invention are used in connection with a hanger bracket Specification of Letters Patent.

Patented Mar. 2t, 19M..

serial no. 539,980.

of tubular or cylindrical formation, through which a shaft 5 extends. tubular bracket varies, as above explained, so that it is desirable that the shaft 5 should be of a maximum length adaptable to hanger brackets of all widths. The shaft coperates with a pair of crank arms 6 and 7, the former of which may be integral with or attached to the adjacent end of a shaft in any usual and well known manner. Obviously, it is necessary to provide a variable attachment for only one end of the shaft in order to adjust the distance between the two crank arms. rhe present invention is concerned particularly with the means provided for making the attachment of the crank arm 7 at the required distance from the crank arm 6.

The crank arm 7 is provided, at its inner end, with a head 8, having formed therein a transversely extending cotter pin hole 9, adapted to receive a cotter pin l0. The cotter pin in the form shown in Fig. la, at its outer end il, is of a substantially cylindrical formation, and the cotter pin is provided in one of its faces with a plurality of longitudinally extending grooves l2, which furnish a plurality of intermediate teeth 13. The pin is tapered down on its toothed side to reduce its thickness at its inner end compared with the thickness of the outer end. rflic longitudinally extending teeth in the Cotter pin cooperate with transversely extending teeth lformed in the relatively flattened end 15 of the shaft 5, which end extends through a hole 1G formedv in the head of the crank arm 7. As shown in Fig. 2, the Cotter pin hole coincides parw tially with the shaft hole, so that when the cotter pin is driven to place, the teeth of the cotter pin will engage with the teeth of the shaft, and this engagement will increase as the cotter pin is driven to place by reason of the wedge action, due to the taper formation of the Cotter pin.

lt is not the intention to limit the invention to the use of a cotter pin of the generally cylindrical formation heretofore described, since the cotte-r pin might be of other than cylindrical formation in cross section. lt will furthermore be understood that it is not the intention to limit the inventio-n as regards the method of securing the wedging action, since this action can obviously be secured in ways other than that specifically described.

rEhe length of this In use, when it is desired to repair a bicycle by substituting a new crank shaft, the shaft 5 with the crank arm 6 will be projected through the usual journal ball bearings carried by the hanger bracket, until the crank arm G and the adjacent end of the shaft are seated and in their proper place. rThis will cause the other toothed end of the shaft to project outwardly beyond the opposite end of the hanger bracket a greater or less distance, depending upon the width of the hanger bracket. And when the parts are thus positioned, the crank arm 7 will be slipped to place and the Cotter pin driven, after which the projecting portion of the shaft can be cut away and discarded. The invention is one which permits the adjustment to be made very quickly, by reason of the fact that the crank arm can be almost instantly slipped to place, without the necessity of employing screw threads, jam nuts, or the like, in making the adjustment. The engagement of the-teeth of the cotter pin with the teeth on the shafts prevents both longitudinal and rotary movement of the crank arm around the shaft, and the wedgelike fornlation of the cotter pin enables it to be driven to place in a manner to firmly and permanently secure the parts together.

l claim:

l. In an adjustable crank hanger, the combination of a shaft, flattened on one side at one of its ends said end being threadless, a crank arm provided with a hole for receiving the flattened threadless end of the shaft and provided with a cottei pin hole partially coinciding with the first mentioned hole, and a cotter pin provided with longitudinally extending teeth, adapted to enter grooves in the face of the flattened end of the shaft, the flattened face of the shaft being provided with transversely extending teeth and intermediate grooves, substantially as described.

2. In an adjustable crank hanger, the combination of a shaft, flattened on one side at one of its ends said end being threadless, a crank arm provided .with a hole for receiving the flattened threadless end of the shaftl and provided with a cotter pin hole partially coinciding with the first inentioned hole, and a cotter pin provided with teeth extending slightly diagonally with respect to the axis of the pin, to constitute a wedge, said teeth being adapted to enter grooves in the face of the flattened end of the shaft, the liattened end of the shaft being provided with transversely extending teeth and intermediate grooves, substantially as described.

In an adjustable crank hanger for bicycles, the combination of a shaft, provided at one end with a crank arm secured at a fixed point to the shaft, and Hattened at its other end on one of its faces said latter end being threadless, a crank arm provided with a hole adapted to receive the flattened threadless end of the shaft and provided with a Cotter pin hole extending transversely with respect to the shaft hole and partially coinciding therewith, and a cot-ter pin provided with teeth on one side adapted to enter grooves on the surface of the shaft when the cotter pin is driven to place, the shaft being provided with transversely eX- tending teeth and intermediate grooves, substantially as described. Y

CHARLES L. JENNESS.

lVitnesses Tiros. A. BANNING, Jr., SAMUEL TN. BANNING.

Copies of this patent may be obtained for ve cents each, by addressing' the Commissioner of Patents Washington, D. C. 

